General Speaker Advice and Recommendations

@wormcycle
It'll be fine. Your damping factor is only marginally affected, and if you're playing at low-ish volumes then you'll never come close to the current limit.
Do you have the option to bi-amp at the back though? You'd be better off using the amps separately like that rather than bridged.

 

not a fan of ls50 either. I had p3esr, atc scm 7 v3 and kef ls 50 for a year at my place

the ls50 was the worst, by far, of the bunch actually.

 

The LS50 is sort of like the Audio Technica M50. It's generally an easy recommendation, performs well overall, and after a while it sort of became a good reference point even though everyone has moved on. Another huge point in its favour is that due to its popularity, it's very easy to buy/sell/trade on the used market.

 

@wormcycle

If Bryston thinks it will survive then you will probably be just fine. Lower than spec impedance for bridged implies a tougher load on the power supply, possible early protection activation or current limiting if run loud and decreased damping factor.

EDIT: Never mind there does not seem to be a gain control on the amp. Not sure if you want to limit the gain control on the amp to only 50% if the pre is sending a loud signal that needs more gain to reproduce fully, wouldn't that cause the amp to clip? Or maybe just be less dynamic than when you ran it in stereo mode?


^ what @Armaegis said,

 

It's actually possible to change the gain in the 2B...
http://bryston.com/PDF/Other/2BLP_GAIN.pdf
Back when I had a stack of these (seriously, I think I had 6 of them at one point), I was going to run a bridged pair with lowered gain for my HE-6... but then sanity took hold and I wound up upgrading a B60r instead.

 

Generally there are two reasons why it's worth being cautious with low impedance loads on power amps. The obvious one is current draw, however it depends more on system sensitivity and general SPL requirements.

Other is oscillation. With low impedance and reactive loads some amps might start to oscillate. Usually protection should kick in, but it's something that's worth keeping in mind.

 

These are pro version so they have gain control knobs separate for each channel, and separate clipping indicators.
I set them to 50% because this is the level where I can use a volume knob on a preamp the most effectively. With 100% I cannot go beyond 10AM it becomes too loud. And at 50% my speakers are entirely silent, when I turn gain to 100% I can just a touch of hiss. It woulkd not matter playing music but it is there.

Yes Totem Hawks have a bi-amping bi-wiring posts and I can set it up this way and try. But why would it be better than bridged and used as two monoblocks? Other than the impedance mismatch issue would go away.

 

Why not try it and see what sounds best? However, as others have said, I doubt there’s any danger to those amps running in bridged mode at lower volumes.

 

That’s the kicker really - why run bridged amps, if you’re not pushing them?

 

Bridging is when you need extra-extra headroom.

Look at it this way. The way you have it now, you're running the amps extra hard into a complex multi driver load. If you bi-amp, you're running the amps within their intended range with a simpler single driver load. It's even arguable that you have better headroom when bi-amped since the power is distributed rather than stacked.

 

Let's not mix up bridging with bi-amping. Bi-amping is essentially creating an active speaker with crossover in the wrong place, but still better than using a single amp for full spectrum. Meaning that even if bass signal is getting your amp to work hard, the tweeter signal won't get contaminated by that.

Bridging essentially means that you get more voltage capability, whilst current capability stays the same (due to load changes). I see sense if you have high-ish impedance loads you need run hard. With higher current draw you do run into copper loss and inductance based distortion products, but maybe there are cases where it's worth it. I just don't see it being worth it on low energy levels, where one amp would be most likely enough.

 

You used biamp in both paragraphs.

 

Thanks for correcting!

 

Anyone know anything about the Superphon DM 200?
I can get one for $400, or maybe trade some of my junk for it.
It looks like a class A amp, 100w/channel into 8 ohm.
Seems like its pretty good, but anyone have any info on it?

 

@murphythecat Too bad your selling your shl5+
I bought them partly because of your words and couldn’t be happier! Hope you find them again or even the 40.1s in your future!

 

The idea was to use two 2B amps as monoblocks?

I will definitely try biamping but first I need to get two XLR Y cables to split the DAC output. I read about a bit on SBAF and other forums and using XLR split from the DAC out to amps is not considered harmful I guess.

 

I hear ya man. I'm one of those nutbars that ran monoblock 2B's for his HE-6 at one point.

There is very little harm in splitting the output from a dac. Here's a cheap option for the splitter and should be available local to you as well:
https://www.long-mcquade.com/4838/P...ound/Link_Audio_XLR-F_to_2x_XLR-M_Y-Cable.htm

 

Looking for suggestions for an amplifier.

Speakers are KEF Reference Model Three (~1994). My current AVR will not work with their 4 ohm impedance. I'm getting them next April and I wanted to start planning for an amp beforehand.

Budget is whatever I can convince my wife to buy, which is probably going to be less than $1000. Was considering a Vidar and Saga at the high end, or something like an Emotiva TA-100 integrated at the low end.

They were demo'd for me with a Mark Levinson monstrosity of the same vintage, but the price was way out of my budget.

 

I made the Y cables from some leftover microphone wire and very crappy XLR connectors. Found some even worse speaker cables but for the woofer it should be OK.
So the setup is far from optimal and I need to listen more to it but what clearly improved is a sound stage. I listened to the test CD and when in the bridged setup the voice was coming from somewhere on the left, or far left, or a bit to the right etc..now I can almost point my finger at the point where I hear it. Promising.
I will keep it like that for few days and go back to bridging and see if it makes a difference. If it works I will need better splitters and the second pair of decent speaker cables
In the biampig configuration Bryston 2B puts 80W per channel into 6 Ohms. Totem Hawks recommended power is 30W-120W whatever it means.

 

Looking at the specs... https://totemacoustic.com/en/hawk/specifications

Your speakers have a sensitivity of 88dB @ 1W (typically defined at 1m listening position).

Every doubling of power gets you 3dB, so you'll hit 103dB at 32W (five doublings). Double twice more to 128W will get you 109dB.

The spec max SPL is defined as 107dB at 2m, which would be 113 dB at 1m (every doubling of distance drops you 6dB, unless you're dealing with line arrays or other funny arrangements).

Looking at the numbers, this makes me think they slapped 30-120W just to get you to 100dB for "headroom" purposes and the limit of 120W so you don't blow the speakers up.